Massachusetts Republican Gabriel Gomez, a private equity investor and former Navy SEAL and aircraft carrier pilot, pulled nomination papers Monday for a Senate bid in the special election, a Republican official confirmed to CQ Roll Call.

Gomez will have until Feb. 27 to collect 10,000 valid signatures of Republican and nonpartisan voters to get on the primary ballot — a daunting challenge for any candidate.

There is only one other GOP candidate vying for the open Senate seat who is seen as likely to get on the ballot: state Rep. Dan Winslow, who announced his campaign last week.

Two congressmen, Edward J. Markey and Stephen F. Lynch, are squaring off for the Democratic nomination for the seat formerly held by their Democratic colleague, Secretary of State John Kerry.